Are you trying to create a fixed length PS data set or variable length? If variable length, 317 does NOT account for the RDW that is required (LRECL must be at least 321). If fixed length, DB2 might be ignoring that because the utility outputs variable length records; you might try using VB instead of FB (don't forget to add the 4 bytes for the RDW).

Otherwise, the link Rohit posted implies (but does not explicitly state) that you cannot provide a record length of SYSREC so it may not be possible to do what you want, anyway.